Place a mailbox on Litigation Hold

Place a mailbox on Litigation Hold to preserve all mailbox content, including deleted items and original versions of modified items. When you place a user' mailbox on Litigation Hold, content in the user's archive mailbox (if it's enabled) is also placed on hold. Deleted and modified items are preserved for a specified period, or until you remove the mailbox from Litigation Hold. All such mailbox items are returned in an In-Place eDiscovery search.

Important:

Litigation Hold preserves items in the Recoverable Items folder in the user’s mailbox. Depending on number and size of items deleted or modified, the size of the Recoverable Items folder of the mailbox may increase quickly. The Recoverable Items folder is configured with a high quota by default. In Exchange Online, this quota is automatically increased when you place a mailbox on Litigation Hold. In Exchange Server 2013, we recommend that you monitor mailboxes that are placed on Litigation Hold on a weekly basis to ensure they don't reach the limits of the Recoverable Items quotas.

To place an Exchange Online mailbox on Litigation Hold, it must be assigned an Exchange Online (Plan 2) license. If a mailbox is assigned an Exchange Online (Plan 1) license, you would have to assign it a separate Exchange Online Archiving license to place it on hold.

As previously explained, when you place a Litigation Hold on a user's mailbox, content in the user's archive mailbox is also placed on hold. If you place a Litigation Hold on an on-premises primary mailbox in an Exchange hybrid deployment, the cloud-based archive mailbox (if enabled) is also placed on hold.

In Exchange Online, the quota for the Recoverable Items folder is automatically increased to 100 GB when you place a mailbox on Litigation Hold. The default size of this folder is 30 GB.

Litigation Hold preserves deleted items and also preserves original versions of modified items until the hold is removed. You can optionally specify a hold duration, which preserves a mailbox item for the specified duration period. If you specify a hold duration period, it’s calculated from the date a message is received or a mailbox item is created. To preserve items that meet your specified criteria, use an In-Place Hold to create a query-based hold. For details, see Create or remove an In-Place Hold.

In the list of user mailboxes, click the mailbox that you want to place on Litigation Hold, and then click Edit .

On the mailbox properties page, click Mailbox features.

Under Litigation hold: Disabled, click Enable to place the mailbox on Litigation Hold.

On the Litigation Hold page, enter the following optional information:

Litigation hold duration (days) Use this box to specify how long mailbox items are held when the mailbox is placed on Litigation Hold. The duration is calculated from the date a mailbox item is received or created. If you leave this box blank, items are held indefinitely or until the hold is removed. Use days to specify the duration.

Note Use this box to inform the user their mailbox is on Litigation Hold. The note will appear in the user’s mailbox if they’re using Outlook 2010 or later.

URL Use this box to direct the user to a website for more information about Litigation Hold. This URL appears in the user’s mailbox if they are using Outlook 2010 or later.

Click Save on the Litigation Hold page, and then click Save on the mailbox properties page.

The example uses the Get-Mailbox cmdlet to retrieve all mailboxes in the organization, specifies a recipient filter to include all user mailboxes, and then pipes the list of mailboxes to the Set-Mailbox cmdlet to enable the Litigation Hold and hold duration.

To place all user mailboxes on an indefinite hold, run the previous command but don’t include the LitigationHoldDuration parameter.

See the More information section for examples of using other recipient properties in a filter to include or exclude one or more mailboxes.

If your organization requires that all mailbox data has to preserved for a specific period of time, consider the following before you place all mailboxes in an organization on Litigation Hold.

When you use the previous command to place a hold on all mailboxes in an organization (or a subset of mailboxes matching a specified recipient filter) only mailboxes that exist at the time that you run the command are placed on hold. If you create new mailboxes later, you have to run the command again to place the new mailboxes on hold. If you create new mailboxes often, you can run the command as a scheduled task as frequently as required.

The Recoverable Items folder has its own storage limit, so items in the folder don’t count towards the mailbox storage limit. As previously explained, preserving mailbox data for a long period of time will result in growth of the Recoverable Items folder in a user’s mailbox and archive. To accommodate for this increase in Exchange Online, the quota for the Recoverable Items folder is automatically increased from 30 GB to 100 GB when you place a mailbox on Litigation Hold.

In Exchange Server 2013, the default storage limit for the Recoverable Items folder is also 30 GB. We recommend that you periodically monitor the size of this folder to ensure it doesn’t reach the limit. For more information, see Recoverable Items folder.

The previous command to place a hold on all mailboxes uses a recipient filter that returns all user mailboxes. You can use other recipient properties to return a list of specific mailboxes that you can then pipe to the Set-Mailbox cmdlet to place a Litigation Hold on those mailboxes.

Here are some examples of using the Get-Mailbox and Get-Recipient cmdlets to return a subset of mailboxes based on common user or mailbox properties. These examples assume that relevant mailbox properties (such as CustomAttributeN or Department) have been populated.